Article dispensing apparatus

Abstract

Dispensing machines are described which are suitable for use in a cold environment. The machines have a plurality of storage locations for supporting articles to be dispensed, each of which includes an electrical heating element. The heating elements can be energized individually and the heat generated by an energized heating element causes an article supported at the respective storage location to be released.

I claim: 
     
       1. A dispensing machine having a plurality of storage locations for supporting articles to be dispensed, each location including a respective electrical heating element (14,118,152), and means for selectively supplying current to the individual heating elements (14,118,152), the heat generated by an energised heating element causing an article to be released from the selected storage location and to pass along a dispensing chute, characterised in that means are provided for monitoring the passage of articles along the dispensing chute and for controlling the power supply to the heating elements of the storage locations to ensure that a selected article is dispensed. 
     
     
       2. A dispensing machine as claimed in claim 1, wherein each storage location comprises a hook from which an article to be dispensed can be suspended, the application of heat to the hook being capable of releasing the suspended article. 
     
     
       3. A machine as claimed in claim 2, wherein the articles to be dispensed are packaged in containers (10) each having a portion (16) from which the container (10) can be suspended, at least the portion (16) of the container (10) from which it can be suspended being made of a material capable of being softened or melted by the application of heat to the hook and wherein the heat applied to the hooks (14) serves to weaken the container so that it may fall off the hook under its own weight. 
     
     
       4. A machine as claimed in claim 2, wherein each hook (14a,14b) is formed of a material that changes shape on the application of heat to permit the article to fall under its own weight. 
     
     
       5. A machine as claimed in claim 4, wherein each hook includes a bimetallic portion (14b) which bends on the application of heat to retract the hook (14a) from the container (10). 
     
     
       6. A machine as claimed in claim 3, wherein each hook (14) is constituted by a heating element, the hook (14) being formed of a length of resistance wire which can be connected across a power supply. 
     
     
       7. A dispensing machine as claimed in claim 1, wherein support means (114,146) are provided at each storage location which are movable under the action of a return force from a first position in which an article to be dispensed is prevented from falling out of the storage location to a second position in which the article is not supported, each storage location further comprising a temperature sensitive detent (116,118; 152) for holding the support means (114, 146) in said first position against the action of the return force, the electrical heating element of the storage location serving to heat the detent to cause the support means to be released when an article is to be dispensed. 
     
     
       8. A machine as claimed in claim 7, wherein the support means of each storage location comprises a shelf (114) on which the article may rest. 
     
     
       9. A machine as claimed in claim 8, wherein the return force on the shelf (114) is exerted by gravity acting to urge the shelf into its second position. 
     
     
       10. A machine as claimed in claim 7, wherein the support means is a clasp having jaws (142,146) for gripping an article to be dispensed, the jaws being held in their closed first position by means of the detent (152,154) which opposes the action of a spring (150) acting to open the jaws. 
     
     
       11. A machine as claimed in claim 10, wherein the jaws have elastomeric pads (142,144) to provide a good frictional grip and to permit the jaws to be closed slightly beyond the point at which the article is firmly gripped between the jaws so as to allow the detent to re-engage the jaws reliably. 
     
     
       12. A machine as claimed in claim 7, wherein the detents include bimetallic strips (118) which are electrically heated. 
     
     
       13. A machine as claimed in claim 7, wherein the storage locations are arranged in rows and columns on vertical trays, and wherein each vertical tray includes a ramp (22) above each storage location so that an article released from one location should not collide with the support means disposed in the same column during its fall. 
     
     
       14. A machine as claimed in claim 2, wherein the storage locations are arranged in rows and columns on vertical trays, and wherein each vertical tray includes a ramp (22) above each storage location so that an article released from one location should not collide with the hook disposed in the same column during its fall. 
     
     
       15. A machine as claimed in claim 1, wherein the storage locations are arranged in rows and columns on vertical trays.